It is known, in the technical sector relating to the coiling of pipes, hanks, and the like into spools, that spools are obtained by coiling the hank onto a reel rotating on a motor-driven hub of a coiling machine. Different models of coilers can automatically coil pipes made of plastic and other materials. The coilers can operate with a completely automatic cycle that includes: (1) extruding the pipe fed in a continuous cycle to a coiling machine; (2) automatically fastening the pipe to be coiled onto the reel by means of a corresponding mechanical device; (3) automatically starting the coiling step, during which a second pipe-guiding device distributes the pipe on the rotating reel; (4) automatically cutting the pipe when the set coiling length is reached; (5) once the spool has been packaged, automatically unloading the roll produced, which is in the form of a pipe that is perfectly coiled to the desired length ready for palletizing operations.
A particular example of such production cycles includes pipes—such as Pex-a pipes used for heating floor panels—for which a high product quality and uniformity of thickness is required.
For this purpose various production methods have been developed, one of these envisaging the use of a constant-pressure air jet supplied inside the pipe which, in order to maintain the required internal pressure, has its free end closed during extrusion and fastening of the pipe to the reel for performing coiling in spool form.
One of the methods for production of such pipes envisages the manual sequences of: (1) manually fitting a cap onto the free end of the pipe as soon as it emerges formed from the extrusion station; (2) manually conveying inside the reel the capped front free end—referred to below as “head end”—and fastening thereof; (3) formation of the spool, by coiling the programmed number of meters of pipe; and (4) cutting the wound pipe.
EP 2,799,382 describes a machine, in which sealing is performed by means of insertion, along the production line, of a pipe-closing cap. During the cutting step, however, it can be necessary for the new head end of the pipe being fed from the extrusion station to be closed in order to maintain the internal pressure. Preliminary crushing of the pipe can be performed upstream of the cutting zone in order to sealingly close the new free end prior to cutting thereof. Once the cut has been performed, a cap is manually fitted onto the new head end of the pipe. Once the reel has completed coiling of the spool with subsequent packaging and unloading thereof, renewed fastening of the new head end of the formed pipe is performed, again manually.
This method, however, involves significant drawbacks, mainly arising from the need to interrupt the continuous coiling cycle with a plurality of manual operations, which result in substantial increases in the machine downtime, with the production efficiency depending to a large extent on the experience and the skill of the operator responsible for performing the cuts and fitting the caps.